Robotics

Robotics is the science and technology of robots, their design, manufacture, and application.Robotics requires a functioning knowledge of electronics, mechanics, and software. A person working in the field is a roboticist. The word robotics was first used in publish by Isaac Asimov, in his science fiction short story "Runaround" (1941).

Although the exterior and capabilities of robots fluctuate enormously, all robots share the features of a mechanical, movable structure under some form of control. The chain is warped of links, actuators and joints which can allow one or more degrees of freedom. Most contemporary robots use open serial chains in which each link connects the one before to the one after it. These robots are called serial robots and often resemble the human arm. A few robots, such as the Stewart platform, exploit closed parallel kinematic chains. Other structures, such as those that mimic the mechanical structure of humans, different animals and insects, are comparatively rare. However, the development and use of such structures in robots is an dynamic area of research. Robots used as manipulators have an end effector mounted on the last link. This end effector can be anything from a welding mechanism to a mechanical hand used to manipulate the environment.

Neural networks

Neural network, also known as a parallel dispersed processing network, is a computing paradigm that is freely modeled after cortical structures of the brain. It consists of consistent processing elements called nodes or neurons that work together to create an output function. The output of a neural network relies on the collaboration of the individual neurons within the network to operate. Processing of information by neural networks is typically done in parallel rather than in series (or sequentially) as in earlier binary computers or Von Neumann machines. Since it relies on its member neurons together to perform its function, a unique property of a neural network is that it can still achieve its overall function even if some of the neurons are not functioning. In other words it is robust to tolerate error or failure. (see fault tolerant) Additionally, neural networks are more readily adaptable to fuzzy logic computing tasks than are Von Neumann machines.

Traditionally, the term neural network has been used to refer to a network of biological neurons. In modern usage, the term is often used to refer to artificial neural networks, which are collected artificial neurons or nodes. Thus the term 'Neural Network' has two distinct connotations:

* Biological neural networks are made up of actual biological neurons that are associated or functionally-related in the peripheral nervous system or the central nervous system

* Artificial neural networks are made up of interconnecting artificial neurons (usually simplified neurons) designed to model (or mimic) some properties of biological neural networks.

Railway

Urban and interurban electric railways using single cars or short trains have more normally used the term railway in their names than regular railroads in the U.S. The first street railway company in Brooklyn, New York City to operate an electric trolley line was the Coney Island & Brooklyn Railroad.

Other English speaking countries
In the United Kingdom the term rail road was often used in the early days of the railways, but by about the 1850s railway had turn into the chosen term, with the term rail road becoming disused. British use of the term railway extended to the rail transport systems that the British built in the British Empire, and elsewhere in the world.

Outside of the U.S., the term railway is used almost completely; however, even there a distinction is sometimes made between predictable railways and street railways or trams, styling the latter light railways from which the modern term light rail is descended.

Flower

A flower is the reproductive structure of those plants classified as angiosperms. The flower structure incorporates the reproductive organs, and its occupation is to create seeds through sexual reproduction. For the higher plants, seeds are the next generation, and serve as the primary means by which persons of a species are dispersed across the landscape. After fertilization, portions of the flower develop into a fruit containing the germ

Flower anatomy
Flowering plants are heterosporangiate and the pollen and ovules are produced in different organs, but these are together in a bisporangiate strobilus that is the typical flower.

A flower is regarded as a modified stem with shortened internodes and behavior, at its nodes, structures that may be highly adapted leaves. In essence, a flower structure forms on a modified shoot or axis with an apical moisten that does not grow constantly. The stem is called a pedicel, the end of which is the tours or container. The parts of a flower are arranged in whorls on the tours. The four main parts or whorls are as follows:

Poppy calyx – the outer whorl of sepals; naturally these are green, but are petal-like in some species.
Corolla – the whorl of petals, which are usually thin, soft and colored to be a focus for insects that help the process of pollination.
Androecium’s– one or two whorls of stamens, each a filament topped by an anther where pollen is produced. Pollen contains the male gametes.
Gynoecium’s – One or more pistils. The female reproductive organ is the carpel: this contains an ovary with ovules. A pistil may consist of a number of carpels merged together, in which case there is only one pistil to each flower, or of a single individual carpel. The sticky tip of the pistil, the stigma, is the receptor of pollen. The supportive stalk, the style becomes the pathway for pollen tubes to grow from pollen grains adhering to the stigma, to the ovules, carrying the reproductive material.

Stamp Collecting

Stamp collecting is the collecting of postage stamps and related objects, such as. It is one of the world's most trendy hobbies, with estimates of the number of collectors ranging up to 20 million in the US alone.

Collecting is not the similar as philately, which is the study of stamps. A philatelist often does, but need not, collect the objects of study, nor is it required to closely study what one collects. Many informal collectors enjoy accumulating stamps without worrying about the tiny details, but the creation of a large or wide-ranging collection generally requires some philatelic knowledge.

History
The primary postage stamp, the One Penny Black, was issued by Britain in 1840. It pictured a young Queen Victoria, was formed without perforations, and accordingly had to be cut from the sheet with scissors in order to be used. While unused examples of the "Penny Black" are quite scarce, used examples are common, and may be purchased for $25 to $150, depending upon state.

Queen Victoria's outline was a staple on 19th century stamps of the British Empire; here on a half-penny of the Falkland Islands, 1891.During the late 1800s many of those collectors, now adults, began to systematically study the available postage stamps and published research works on their manufacture, plate flaws, etc.

Sea water

Sea water is water as of a sea or ocean. On normal, sea water in the world's oceans has a salinity of ~3.5%. This means that for every 1 liter of sea water there are 35 grams of salts dissolved in it. This can be expressed as 0.6M NaCl. Water with this level of osmolality is, of course, not potable.

Sea water is not consistently saline throughout the world. The planet's freshest sea water is in the Gulf of Finland, part of the Baltic Sea. The most saline open sea is the Red Sea, where high temperatures and controlled circulation result in high rates of surface evaporation and there is little fresh inflow from rivers. The salinity in isolated seas can be considerably greater.

The thickness of sea water is between 1020 and 1030 kg/m3. Due to chemical buffering, seawater pH is limited to the range 7.5 to 8.4.

Ocean salinity

Scientific theories behind the beginning of sea salt started with Sir Edmond Halley in 1715, who proposed that salt and other minerals were carried into the sea by rivers, having been leached out of the ground by rainfall runoff. Upon reaching the ocean, these salts would be retained and determined as the process of vanishing removed the water. Halley noted that of the small number of lakes in the world without ocean outlets, most have high salt content. Halley termed this process "continental weathering".

Halley's theory is partially correct. In addition, sodium was leached out of the ocean floor when the oceans first formed. The presence of the other leading element of salt, chloride, results from "out gassing" of chloride with other gases from Earth's interior via volcano’s and hydrothermal vents. The sodium and chloride consequently became the most abundant constituents of sea salt.
Ocean salinity has been stable for millions of years, most likely as an importance of a chemical/tectonic system which recycles the salt. Since the ocean's creation, sodium is no longer leached out of the ocean floor, but instead is captured in sedimentary layers covering the bed of the ocean. One theory is that plate tectonics result in salt being forced under the continental land masses, where it is again gradually leached to the surface.

Contact lens

A contact lens (also known as a "contact") is a corrective, cosmetic, or sometimes protective lens located on the cornea of the eye.Contact lenses are obtainable in a number of varieties, including hard and soft. Hard contacts are classically not disposable, while soft contacts often are. Some soft contacts are also well-known as extended wear lenses. Contact lenses (both soft and hard) are made a variety of types of polymers, the latest containing some variant of silicone hydrogel. Previously, hard contact lenses were made of a polymer known as PMMA. They have since been replaced by rigid gas-permeable (RGP) contact lenses. Many contact lenses are made of hydrophilic (water-absorbing) materials, thereby allowing oxygen to reach the cornea, and make the lens more comfortable to wear.Heavily tinted contacts are tinted to change the color of the iris, and are used for cosmetic reasons. Some standard contact lenses are somewhat tinted in order to make them more visible for handling purposes.